1. Place one of your pie dough rounds into a 9-inch pie plate.2. Preheat oven to 375 degrees3. Peel, halve, and core pears. Very thinly slice 2 pears lengthwise, and cut remaining pear into wedges.4. Toss together pears, cranberries, sugar, cornstarch, and salt in a large bowl. Using the tip of a paring knife, scrape vanilla seeds over pear mixture, and toss until seeds have been evenly incorporated. Pour filling into piecrust. Dot filling with butter.5. Cover pie with second round of pie dough (either cut slits or make a lattice). Lightly brush top of piecrust with heavy cream.6. Place a foil-lined baking sheet on lower oven rack to catch any juices. Place pie on middle rack, and bake until crust is golden brown and juices are bubbling gently, about 90 minutes. Let pie cool on a wire rack for 5 minutes.7. Meanwhile, heat preserves in a saucepan over medium heat until warm. Puree in a food processor until smooth. Brush warm pie with the warm apricot glaze. Let cool completely on rack.